For those who have been diagnosed and are curious about whether a trial is a good fit, it’s worth doing some research and talking with your physician about the possibility. Here are some basics as a solid starting point.

What the ‘phases’ of a clinical trial mean

There are four phases of clinical trials. Phase one assesses the safety of a drug, device, or other intervention. It usually includes a small number of participants — often fewer than 100.

“Phase one trials used to have a negative connotation, because patients sometimes believed you would be ramping up dosage of a drug until they saw bad side effects,” says Jack F. Jacoub, M.D., medical oncologist and medical director of MemorialCare Cancer Institute at Orange Coast Memorial Medical Center, Fountain Valley, California. “That’s simply not the case. You’re not seen as a lab rat in these trials, you’re viewed as a vital participant in a very important process toward improving medicine. That’s true at every phase.”

In phase two, with safety in place, the drug or device is evaluated for efficacy. This involves more participants, and may use a “control” group that receives a placebo or standard treatment. Most often, though, there is no placebo — simply different levels of medication dosages or the same dose applied to multiple types of conditions.

“There’s a common misconception that some people in the trial will get a placebo and therefore not be treated for their condition,” says Dr. Jacoub. “But there will always be a standard of care in place.”

Phase three brings in several hundred to several thousand participants and uses randomized and blind testing to determine whether the treatment works for a larger number of people. Phase three also looks more closely at potential adverse reactions, such as significant side effects.

At that point, the drug, device, or intervention can then be approved for use among a wider patient population, and may enter phase four, which looks at long-term effectiveness.

For every phase, there is an initial process called “informed consent.” During that period, you’ll have the chance to ask the researchers questions — although you can certainly do that during the trial as well. Informed consent is required by federal law for research institutions, to ensure that patients understand the requirements, risks, and benefits of participating in a specific trial.

No matter what phase you join, keep in mind that you can drop out anytime. Joining a trial doesn’t mean you’re automatically “locked in” until the end. Participation is always voluntary.

What to consider before joining a trial

Even if you’ve qualified for a trial based on the specific research criteria of that trial, there are still several factors to keep in mind before joining. For example, a major aspect is what type of support you have from caregivers, says Marlon Saria, Ph.D., R.N., advanced practice nurse researcher at the John Wayne Cancer Institute, Santa Monica, California.

Dr. Saria has been involved with clinical trials for eight years, with usually around 20 trials open simultaneously. Those who seem to do the best with trials, he notes, are people who have engaged and organized caregivers.

“If you have a diagnosis like cancer, you already have a complex medical issue,” he says. “You’re dealing with pain management, treatment, possible medication schedules, testing, and appointments. Adding a clinical trial into that gives you more to track and remember. It’s best to have support for that.”

Also, an active caregiver can be observant about potential side effects. Dr. Saria has seen patients leave clinical trials because they haven’t noticed problems until their side effects were quite advanced. But if those effects are caught early, they can be addressed and allow you to stay in the trial.

For those with lymphoma who don’t have an involved caregiver, help is available through the Leukemia & Lymphoma Society (LLS), says Alissa Gentile, R.N., director of the organization’s Clinical Trial Support Center. The LLS service has nurses who follow patients through clinical trials and help them through the process.

Keep financial aspects in mind

Another consideration when thinking about whether to join a trial may be the financial impact. In some cases, participants receive payment, but more often, the pharmaceutical or device company involved in the treatment only pays for the treatment used in the clinical trial.

That doesn’t cover expenses like hospital stays, doctor and nurse time, and other costs, including some drugs costs, according to Gentile.

“There is a large misconception that clinical trials will cover all expenses, and unfortunately, that’s rarely true,” she says. “That’s why it’s important to look at potential costs and insurance coverage when evaluating whether to join a trial. Otherwise, you may have an unpleasant surprise when you find that you have to cover costs that you didn’t expect.”

Knowing the aspects of a trial — how long the trial will be conducted, how current treatment will be affected, which out-of-pocket expenses will be involved, and what factors would cause you to be dropped from the trial — is a crucial part of making the decision about whether a trial seems like a good fit for you.

Elizabeth Millard

Elizabeth Millard is a freelance journalist specializing in health, wellness, fitness, and nutrition. Her articles have appeared in SELF, Men’s Health, CNN, MyFitnessPal, and WebMD, and she has worked on patient education materials for Mayo Clinic and UnitedHealth Group. She’s also a registered yoga teacher and organic farmer.